UWE Bristol Engineering showcase 2015

Benedict Merrett
BENG Electronic and Electrical Engineering
Project Supervisor
Nigel Gunton
Investigation Into the Automisation of an Aquaponics System and the
Scalability of That System.
Design
The system is designed to reduce energy consumption through clever design
features. Having the plant tank above the fish tank for instance, allows the
water in the plant tank to drain without the use of a pump.
The design uses a pump to circulate water up to the plant tank, a simple siphon
will drain all the water from the tank. The use of a siphon as opposed to a valve
will reduce the overall power consumption of the system.
In order to regulate the fish tank temperature there is a temperature sensor
located in the middle of the tank. There is a heating element to increase the
temperature. The cooling system uses a pump to force water though an
external pipe coil.
A RGB sensor serves two functions: measuring turbidity and chemical analysis
of the tanks. The sensor will be mounted to the side of the fish tank with a
servo. This allows the sensor to be flat against the tank wall for turbidity
measurements and angled back for chemical tests. If the turbidity or chemical
readings are out of limits a warning message will be displayed on the LCD.
The chemical analysis is
carried out using a robot
arm to dip paper strips
into each tank and place
them in front of the RGB
sensor. The paper strips
will be dispensed by a
printer-like device which
dispenses test strips one
at a time. The system
uses a Altera Cyclone 3
FPGA mounted on aDE0
as the CPU. VHDL and C
code was written and
programed to the DE0.
Left is a schematic of the
electronics.
Results
The system implemented is automated and meets most of the requirements.
However it does not run the test routine as early on in the testing phase it was
found that the robot arm was not suitable. The implemented system is shown
below.
Scalability
It was determined that the system is scalable for large scale food production
with a couple of modifications. It was also deemed non scalable for interstellar
aquaponic systems as there are a number of features that would need to be
added. However this project does show that a FPGA controlled would be
suitable for this application.
Project summary
The project was an idea brought about by a
free lecture. The goal of this project is to build
a fully automated aquaponic system
controlled by an FPGA and look at the
scalability of the system for commercial food
production and long term space travel.
Project Objectives
Build an aquaponic system to these
requirements:
• Maintain a constant temperature in the
plant tank.
• Take readings of chemicals in fish tank and
plant tank, (Acidity, Ammonia, Nitrate and
Nitrite).
• Monitor turbidity of the water.
• Provide feedback to user.
• Circulate water from fish tank to plant tank
(as a minimum, the full volume of water
every two hours).
And assess the Scalability of the implemented
system for commercial food production and
long term space exploration
Project Conclusion
The report reaches the conclusion that the system
designed could be scaled up for use in commercial
systems. However, although it would be possible to
have an FPGA based aquaponics system in space, due
to the complexity of the system needed for space
exploration too many modifications would be needed
to deem it scalable for this purpose.